of course i will be kind and the referrence from i was saying that are:
1) Prevalence of Wikipedia reference-linkfacet joint pain in chronic spinal p... [BMC Musculoskelet Disord. 2004] - PubMed result
2)Age-related prevalence of facet-joint involvement ... [Pain Physician. 2008] - PubMed result

The first article is the original survey collecting patients from ALL spine-related problems (instead on focusing on one particular area of the spine) and the second is a secondary-retrospective analysis of the first article...few studies compare simultaneously the 3 specific areas of the spine namely cervical,thoracic,lumbar....The only critisism on these studies is that there was no comparative evaluation of other possible pain-generated structures like the disc,through a discogram, and despite the authors have mentioned the FALSE-POSITIVE rate of a facet-joint block injection we cannot rule out other potential causes of pain....
The only safe conclusion is that CERVICAL SPINE has much more FACET- joint pain than LUMBAR SPINE and this is more obvious in younger ages which can be explained by the fact that Cervical disc is almost fibrosous by the age of early adulthood and not acting as its lumbar counterpart...Its my explanation why facet joint-pain is more often in neck area......
But we should never in clinical practice trying to diagnose patients as "discogenic" ,"facet-joint" pain or whatever....When u get patients in a self-mobilisation programm (adding clinician forces where NECESSARY, see one of my older posts,where i didnt follow this LAW,not just a rule) u surely get good results,no matter if the pain comes from disc,facet,ligaments and muscles!!!